Hole transport and photoluminescence in Mg-doped InN

Journal Article · Wed Mar 24 04:00:00 EDT 2010 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3427564· OSTI ID:986242

Miller, N; Ager, III, J W; Smith, III, H M; Mayer, M A; Yu, K M; Haller, E E; Walukiewicz, W; Schaff, W J; Gallinat, C; Koblmuller, G; Speck, J S

Hole conductivity and photoluminescence were studied in Mg-doped InN films grown by molecular beam epitaxy. Because surface electron accumulation interferes with carrier type determination by electrical measurements, the nature of the majority carriers in the bulk of the films was determined using thermopower measurements. Mg concentrations in a"window" from ca. 3 x 1017 to 1 x 1019 cm-3 produce hole-conducting, p-type films as evidenced by a positive Seebeck coecient. This conclusion is supported by electrolyte-based capacitance voltage measurements and by changes in the overall mobility observed by Hall effect, both of which are consistent with a change from surface accumulation on an n-type film to surface inversion on a p-type film. The observed Seebeck coefficients are understood in terms of a parallel conduction model with contributions from surface and bulk regions. In partially compensated films with Mg concentrations below the window region, two peaks are observed in photoluminescence at 672 meV and at 603 meV. They are attributed to band-to-band and band-to-acceptor transitions, respectively, and an acceptor binding energy of ~;;70 meV is deduced. In hole-conducting films with Mg concentrations in the window region, no photoluminescence is observed; this is attributed to electron trapping by deep states which are empty for Fermi levels close to the valence band edge.

• Research Organization: Ernest Orlando Lawrence Berkeley National Laboratory, Berkeley, CA (US)
• Sponsoring Organization: Materials Sciences Division
• DOE Contract Number: AC02-05CH11231
• OSTI ID: 986242
• Report Number(s): LBNL-3810E
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 11 Vol. 107; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BINDING ENERGY
CAPACITANCE
ELECTRONS
FERMI LEVEL
HALL EFFECT
MOLECULAR BEAM EPITAXY
PHOTOLUMINESCENCE
TRANSPORT
TRAPPING
VALENCE
WINDOWS